﻿// Copyright 2009-2024 Josh Close
// This file is a part of CsvHelper and is dual licensed under MS-PL and Apache 2.0.
// See LICENSE.txt for details or visit http://www.opensource.org/licenses/ms-pl.html for MS-PL and http://opensource.org/licenses/Apache-2.0 for Apache 2.0.
// https://github.com/JoshClose/CsvHelper
using System.Collections;
using System.Diagnostics;
using System.Linq.Expressions;
using System.Reflection;

namespace CsvHelper.Configuration;

/// <summary>
/// A collection that holds <see cref="MemberMap"/>'s.
/// </summary>
[DebuggerDisplay("Count = {list.Count}")]
public class MemberMapCollection : IList<MemberMap>
{
	private readonly List<MemberMap> list = new List<MemberMap>();
	private readonly IComparer<MemberMap> comparer;

	/// <summary>
	/// Gets the number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </summary>
	/// <returns>
	/// The number of elements contained in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </returns>
	public virtual int Count => list.Count;

	/// <summary>
	/// Gets a value indicating whether the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
	/// </summary>
	/// <returns>
	/// true if the <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only; otherwise, false.
	/// </returns>
	public virtual bool IsReadOnly => false;

	/// <summary>
	/// Initializes a new instance of the <see cref="MemberMapCollection"/> class.
	/// </summary>
	public MemberMapCollection() : this(new MemberMapComparer()) { }

	/// <summary>
	/// Initializes a new instance of the <see cref="MemberMapCollection"/> class.
	/// </summary>
	/// <param name="comparer">The comparer to use when sorting the member maps.</param>
	public MemberMapCollection(IComparer<MemberMap> comparer)
	{
		this.comparer = comparer;
	}

	/// <summary>
	/// Returns an enumerator that iterates through the collection.
	/// </summary>
	/// <returns>
	/// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
	/// </returns>
	/// <filterpriority>1</filterpriority>
	public virtual IEnumerator<MemberMap> GetEnumerator()
	{
		return list.GetEnumerator();
	}

	/// <summary>
	/// Returns an enumerator that iterates through a collection.
	/// </summary>
	/// <returns>
	/// An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.
	/// </returns>
	/// <filterpriority>2</filterpriority>
	IEnumerator IEnumerable.GetEnumerator()
	{
		return GetEnumerator();
	}

	/// <summary>
	/// Adds an item to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </summary>
	/// <param name="item">The object to add to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	///                 </param><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
	///                 </exception>
	public virtual void Add(MemberMap item)
	{
		list.Add(item);
		list.Sort(comparer);
	}

	/// <summary>
	/// Adds a range of items to the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </summary>
	/// <param name="collection">The collection to add.</param>
	public virtual void AddRange(ICollection<MemberMap> collection)
	{
		list.AddRange(collection);
		list.Sort(comparer);
	}

	/// <summary>
	/// Removes all items from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </summary>
	/// <exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only. 
	///                 </exception>
	public virtual void Clear()
	{
		list.Clear();
	}

	/// <summary>
	/// Determines whether the <see cref="T:System.Collections.Generic.ICollection`1"/> contains a specific value.
	/// </summary>
	/// <returns>
	/// true if <paramref name="item"/> is found in the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false.
	/// </returns>
	/// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	///                 </param>
	public virtual bool Contains(MemberMap item)
	{
		return list.Contains(item);
	}

	/// <summary>
	/// Copies the elements of the <see cref="T:System.Collections.Generic.ICollection`1"/> to an <see cref="T:System.Array"/>, starting at a particular <see cref="T:System.Array"/> index.
	/// </summary>
	/// <param name="array">The one-dimensional <see cref="T:System.Array"/> that is the destination of the elements copied from <see cref="T:System.Collections.Generic.ICollection`1"/>. The <see cref="T:System.Array"/> must have zero-based indexing.</param><param name="arrayIndex">The zero-based index in <paramref name="array"/> at which copying begins.</param><exception cref="T:System.ArgumentNullException"><paramref name="array"/> is null.</exception><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="arrayIndex"/> is less than 0.</exception><exception cref="T:System.ArgumentException">The number of elements in the source <see cref="T:System.Collections.Generic.ICollection`1"/> is greater than the available space from <paramref name="arrayIndex"/> to the end of the destination <paramref name="array"/>.</exception>
	public virtual void CopyTo(MemberMap[] array, int arrayIndex)
	{
		list.CopyTo(array, arrayIndex);
	}

	/// <summary>
	/// Removes the first occurrence of a specific object from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </summary>
	/// <returns>
	/// true if <paramref name="item"/> was successfully removed from the <see cref="T:System.Collections.Generic.ICollection`1"/>; otherwise, false. This method also returns false if <paramref name="item"/> is not found in the original <see cref="T:System.Collections.Generic.ICollection`1"/>.
	/// </returns>
	/// <param name="item">The object to remove from the <see cref="T:System.Collections.Generic.ICollection`1"/>.
	///                 </param><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.ICollection`1"/> is read-only.
	///                 </exception>
	public virtual bool Remove(MemberMap item)
	{
		return list.Remove(item);
	}

	/// <summary>
	/// Determines the index of a specific item in the <see cref="T:System.Collections.Generic.IList`1"/>.
	/// </summary>
	/// <returns>
	/// The index of <paramref name="item"/> if found in the list; otherwise, -1.
	/// </returns>
	/// <param name="item">The object to locate in the <see cref="T:System.Collections.Generic.IList`1"/>.
	///                 </param>
	public virtual int IndexOf(MemberMap item)
	{
		return list.IndexOf(item);
	}

	/// <summary>
	/// Inserts an item to the <see cref="T:System.Collections.Generic.IList`1"/> at the specified index.
	/// </summary>
	/// <param name="index">The zero-based index at which <paramref name="item"/> should be inserted.
	///                 </param><param name="item">The object to insert into the <see cref="T:System.Collections.Generic.IList`1"/>.
	///                 </param><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.
	///                 </exception><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.
	///                 </exception>
	public virtual void Insert(int index, MemberMap item)
	{
		list.Insert(index, item);
	}

	/// <summary>
	/// Removes the <see cref="T:System.Collections.Generic.IList`1"/> item at the specified index.
	/// </summary>
	/// <param name="index">The zero-based index of the item to remove.
	///                 </param><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.
	///                 </exception><exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.Generic.IList`1"/> is read-only.
	///                 </exception>
	public virtual void RemoveAt(int index)
	{
		list.RemoveAt(index);
	}

	/// <summary>
	/// Gets or sets the element at the specified index.
	/// </summary>
	/// <returns>
	/// The element at the specified index.
	/// </returns>
	/// <param name="index">The zero-based index of the element to get or set.
	///                 </param><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.Generic.IList`1"/>.
	///                 </exception><exception cref="T:System.NotSupportedException">The member is set and the <see cref="T:System.Collections.Generic.IList`1"/> is read-only.
	///                 </exception>
	public virtual MemberMap this[int index]
	{
		get { return list[index]; }
		set { list[index] = value; }
	}

	/// <summary>
	/// Finds the <see cref="MemberMap"/> using the given member expression.
	/// </summary>
	/// <typeparam name="T">The <see cref="System.Type"/> the member is on.</typeparam>
	/// <param name="expression">The member expression.</param>
	/// <returns>The <see cref="MemberMap"/> for the given expression, or null if not found.</returns>
	public virtual MemberMap? Find<T>(Expression<Func<T, object?>> expression)
	{
		var member = ReflectionHelper.GetMember(expression);
		return Find(member);
	}

	/// <summary>
	/// Finds the <see cref="MemberMap"/> using the given member.
	/// </summary>
	/// <param name="member">The member.</param>
	/// <returns>The <see cref="MemberMap"/> for the given expression, or null if not found.</returns>
	public virtual MemberMap? Find(MemberInfo member)
	{
		var existingMap = list.SingleOrDefault(m =>
		   m.Data.Member == member ||
		   m.Data.Member != null &&
		   m.Data.Member.Name == member.Name &&
		   (
			   m.Data.Member.DeclaringType!.IsAssignableFrom(member.DeclaringType) ||
			   member.DeclaringType!.IsAssignableFrom(m.Data.Member.DeclaringType)
		   )
		);

		return existingMap;
	}

	/// <summary>
	/// Adds the members from the mapping. This will recursively
	/// traverse the mapping tree and add all members for
	/// reference maps.
	/// </summary>
	/// <param name="mapping">The mapping where the members are added from.</param>
	public virtual void AddMembers(ClassMap mapping)
	{
		AddRange(mapping.MemberMaps);
		foreach (var refmap in mapping.ReferenceMaps)
		{
			AddMembers(refmap.Data.Mapping);
		}
	}
}
